An Islamist group claimed responsibility for last weekend’s suicide car bombings in central Damascus to avenge the Syrian regime’s “massacre of Sunnis,” in a statement posted online Wednesday.

Al-Nusra Front to Protect the Levant, in the statement on Islamist websites, said its militants carried out “a series of military operations... especially the air force security” buildings of the “criminal regime” in Damascus.

The attacks were “in response to the continued shelling by the regime of residential districts of Homs, Idlib, Hama and Daraa,” it said, listing major centers of opposition across Syria.

“We will later respond to the crimes carried out by the regime” in the central city of Homs, it warned, demanding that the regime, led by Alawites, an offshoot of Shiite Islam, “stop its massacres of Sunnis.”

AFP could not verify the authenticity of the statement.

The Al-Nusra Front to Protect the Levant first emerged at the end of February to claim suicide bombings in Damascus and Aleppo, Syria’s second largest city.

The group said the attacks were “to avenge the people of Homs” besieged by regime forces.

A video posted on jihadist forums showed footage of the destruction caused by the January 6 car attack in Damascus that killed 26 people, and by a twin suicide car bombing in Aleppo on February 10 that killed 28 people.

A double suicide car bombing targeting security installations in Damascus on Saturday killed 27 people, the interior ministry said, a day before a similar attack killed two more in Aleppo, Syria’s commercial hub.

Syria blamed the bombings on “armed terrorist gangs” which it holds responsible for the year-old bloodshed in the country that monitors say has cost more than 9,100 lives in a brutal crackdown on dissent.

It has also pointed to an al-Qaeda role in the violence, while opposition activists have accused the Damascus regime of stage-managing attacks such as the car bombings to cause inter-sectarian strife.

According to the U.S.-based monitors SITE Intelligence Group, the terror network came out on January 23 with a message calling for armed struggle against the regime.

Last month, U.S. spy chief James Clapper said al-Qaeda’s branch in Iraq had probably carried out the January and February suicide bombings in Syria, having infiltrated rebel forces fighting President Bashar al-Assad’s regime.

The bomb attacks “had all the earmarks of an al-Qaeda-like attack,” Clapper said at the time. “And so we believe al-Qaeda in Iraq is extending its reach into Syria.”

Al-Qaeda leader Ayman al-Zawahiri has expressed support for Syrian rebels.